Monday, July 21, 2003
I was back on the waters off Kaikoura again this morning at 9:15 with Jenny and Jeanie, this time on Lissodelphis, a 13-meter (42 foot) Dolphin Encounter boat. The harbor at South Bay holds just a few Whalewatch Kaikoura boats (four slips) and the Coast Guard boat, so all other boats, even the big ones, are launched each morning by trailers pulled by big tractors and hauled out again each night. The captains are amazingly adept at getting the boats on the trailer; they just drive right on!
We met Simon, the captain, and Fi (short for Fiona), the guide. There were seven swimmers and three spectators today. We left South Bay and entered the three-meter swells. Sloppy. At first I wondered if I might get sick, but soon felt okay.
The dolphins weren't in as festive a mood as they were Friday. Simon estimated that there were about 500 animals and we saw quite a few, but there was little leaping-so little we didn't collect behavior data on them. They were also quite spread out, which was a bit disappointing for the swimmers, who were bundled in wetsuits, outfitted with mask, snorkel, and fins, and told to make noise and hum. Their singing, calling, hooting, and yelling through the snorkels was quite amusing. Some dolphins did come through, but it's easy to see how you can miss them if you're looking the wrong way. The boat did three drops, and recorded the start time, end time, number of swimmers in the water and environmental conditions. After an hour or so, the swimmers came out of the water and we followed the dolphins for a while. They began to get closer and swam around the boat a lot. It was easier to tell the difference between juveniles and adults was so high.
In the afternoon, I received my first introduction to the Fin Scan program. In the past, all photographs of fin were shot with film, developed, and catalogued in albums. To find out whether a new fin picture of a fin matched the databse, someone needed to thumb through the album searching for similar pictures. Then digital photography was introduced, Fin Scan was developed, and life became easier and far more efficient for researchers. First all the frames taken in a day are downloaded onto the computer and sorted. Those that are unusable are deleted. Next, the edge of each fin is traced roughly using the mouse and refined using an editing feature. This creates an outline showing the unique nicks and dings found in the fins of most adult dolphins. To find a match, in the database, the user needs only to direct the program to search, and within seconds, possible matches appear on the screen. The human element enters again at this point, with the user deciding which fin the new photo matches best. A researcher or volunteer who discovers a previously unidentified dolphin has the privilege of "naming" the dolphin.
Fin identification has, among other things, allowed the researchers to learn that Kaikoura's summer dolphins move north in the winter, and had potential to identify many other associations and movements of individual animals.